Multi-function convertible trailer and towing structure

ABSTRACT

A trailer having a framework configured for selectively switching between a wheel-based towing mechanism and a ski-based towing mechanism and wherein the trailer framework is lightweight and configured for supporting an enclosed trailer that may be constructed of lightweight composite paneling. The trailer framework can also be used with a pivotable and removable tow-bar where the tow-bar is configured with a plurality of pivotable attachment points for pivotably securing to the framework. The tow-bar is also connectable to any tow-vehicle and can be removed from the tow-vehicle and the trailer framework when not in use, or can be pivoted upwardly about the trailer framework for storage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. non-provisional applicationSer. No. 15/418,897, filed on Jan. 30, 2017 which claims priority fromU.S. provisional application Ser. No. 62/289,203, filed on Jan. 30, 2016and claims priority from U.S. provisional patent application Ser. No.62/289,999, filed on Feb. 2, 2016, the contents of which are hereinincorporated in their entities.

BACKGROUND

The present invention relates to trailers. More specifically, theinvention relates to an enclosed convertible trailer for use in variousactivities or for use as a utility trailer and a towing structure thatmay be used with said trailer.

Generally, enclosed trailers are towed by vehicles such as trucks orvans. The trailers have a pair of wheels allowing for towing, howeverthe wheels limit the ability of smaller vehicles, even light weighttrucks, to tow an enclosed trailer or uneven, muddy or otherwise roughterrain.

Trailer frameworks also generally include an integral portion extendingoutwardly on one end that is configured for connection to the towingvehicle. When not in use, the towing end remains extending outwardlyfrom the trailer and when in use, present a tripping or injury hazard tothose walking near the trailer or the framework.

SUMMARY

An aspect of the present disclosure relates to a light weightconvertible trailer framework, where the framework can support an openor an enclosed trailer. The framework is a wheeled framework for atrailer. The wheeled framework is further adapted with a plurality ofskis such that the framework and thus the trailer supported thereon canbe towed using either the wheels or the skis and the method of towingcan be selected given the terrain conditions. The ski mode, when thetrailer framework is towed by contact of the skis sliding over theground can be used without requiring removal of the wheels. The wheelscan be used for towing while the skis also remain connected to theframework (but not in contact with the ground surface). The enclosedtrailer may be comprised of composite panels forming walls, a base androof to further add to the light weight nature of the entire trailer.

The framework may be comprised of a plurality of metal tubes, such asaluminum. The tubing provides a framework for supporting a trailerenclosure thereon. At least one pair of wheels are operably attached tothe framework, for example, on opposing sides of a distal end (oppositethe towing attachment end) of the trailer. The wheels are operablyattached to the framework via an axle, however this axle and/or thewheel connections may also be configured to rotate such that rotation ofthe axle and/or wheel connections raises or lowers the wheels withrespect to their connection to the framework. Thus, rotation isconverted to vertical movement of the wheels.

A bottom or ground facing surface of at least one section of theframework is adapted with at least one plate configured to contact theground. The plate(s) may co-extend a portion of the length of thetrailer away from the tow-connection end towards the wheels, however theplate(s), hereinafter referred to as a ski(s) are positioned secured tothe framework and positioned between (inside) the pair of wheels so asnot to inhibit use of the wheels. When the wheels are raised, the skiscontact the ground and the trailer may be pulled by the skis. When thewheels are lowered, the skis are raised off of the ground and thetrailer may be pulled by the wheels. The skis may be metal or plasticand may be coated with a material to reduce the coefficient of frictionbetween the skis and the ground.

Another aspect of the present disclosure relates to a tow-bar that ispivotable between a stowed position and an in-use position, where thetow-bar is also easily removable from connection with the trailerframework and also from connection with the towing vehicle. The tow-baris pivotably and removably connected at a plurality of spaced apartlocations to a trailer framework. A first end of the tow-bar comprisesat least two terminal ends of diverging arms where the terminal ends ofthese arms are configured to pivotably connect to the framework of thetrailer. The second, opposing end of the tow bar comprises convergingends of the arms in an apex, where a connector for a tow vehicle is alsopositioned. This second end is configured for the tow-bar to be alsoremovably attached at the second end via the vehicle connector to a towvehicle.

The tow-bar further comprises a rigid member or arm extending from thefirst end to the second end of the tow-bar, where the rigid member maybe positioned between the diverging arms. At a terminal end of the rigidmember, which is positioned at the first end of the tow-bar, theterminal end of the rigid member can be configured to connection to thetrailer framework and this connection may also be pivotable. An opposingfirst end of the rigid member meets the apex of the tow-bar arms at thesecond end and can be secured to the apex with a pin or clamp, thusproviding stability to the tow-bar when the tow-bar is in the useposition. The tow bar may pivot with the tow-bar as being connected tothe second end of the tow bar to the stored position, or the rigidmember may pivot independently of the tow-bar by only being connected tothe framework and not secured to the tow-bar. The use position is aposition where the tow-bar is concurrently connected to the tow-vehicleand the framework of the trailer, allowing for the trailer to be towed.The rigid member may then be secured to both the framework and thetow-bar itself for stability. In the stowed position, the tow-bar isconnected only to the framework and is pivoted or rotated about thegenerally horizontal axis of the framework, such that, for example, thetow-bar is rotated upwardly and out of the way as it may be restingvertically against an trailer wall supported by the framework. Thetow-bar can also be easily removed from both the framework and the towvehicle and thus stored when not in use to prevent theft.

The tow-bar may be an aluminum or metal extrusion where components arewelded or otherwise secured together and each of the pivotableconnections, such as the pivotable attachment points at the first endmay comprise pins for preventing or limiting the extent of the pivotingwhen the tow-bar is in use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a framework and running gear of aconvertible trailer according the present disclosure.

FIG. 2 is a perspective view of the convertible trailer in a “wheelmode.”

FIG. 3 is a left side view of the convertible trailer in wheel mode.

FIG. 4 is a perspective view of a bottom framework of the trailer havingintegrated skis.

FIG. 5 is a rear view of convertible trailer.

FIG. 6 is a left side view of the convertible trailer with axles rotatedfor ski mode.

FIG. 7 is a left side view of the convertible trailer with axles removedfor ski mode.

FIG. 8 is a perspective view of the convertible trailer in ski mode.

FIG. 9 is a perspective view of the convertible trailer framework withtire, wheel, and axle assemblies removed.

FIG. 10 is a perspective view of a tow-bar assembly and trailerframework in a rigid configuration.

FIG. 11 is a side view of the tow-bar location relative the trailerframework while in the rigid configuration.

FIG. 12 is a perspective view of the tow bar assembly in the rigidconfiguration.

FIG. 13 is a side view of the tow-bar location relative the trailerframework while in the pivoting configuration.

FIG. 14 is a perspective view of the tow-bar assembly and trailerframework in the pivoting configuration.

FIG. 15 is a perspective view of the tow-bar assembly in the pivotingconfiguration.

FIG. 16 is a perspective view of an additional tow-bar assembly andtrailer framework in a rigid configuration.

DETAILED DESCRIPTION

A convertible trailer is described herein and comprises a frameworkhaving integrated skis that also accepts tire, wheel, and axleassemblies such that the trailer is configured for dual towing modes,selectable based on changing environmental conditions. The trailer is aconvertible trailer that can be towed in a “wheel mode” or “a ski mode”as described herein.

Also described is a tow-bar assembly for coupling the framework of a towvehicle, wherein the tow-bar assembly is convertible between rigid andpivoting configurations.

The tow-bar assembly includes a tow-bar attached to the trailerframework (and usable with any pre-existing trailer) at two or morepoints that lie upon the same axis which allow for free rotation of thetow-bar while the tow-bar is in a pivoting configuration. Thus, thisforms a trailer which behaves similar in fashion to a sled, whichgreatly reduces the hitch weight on the tow vehicle. The tow-bar alsocomprises a rigid member, such that when pinned in one or moreattachment points between said tow-bar and trailer frame, the rigidmember creates a rigid frame configuration, allowing the tow-bar andhitch to behave similar to a traditional trailer tongue.

The trailer described herein is a lightweight enclosed trailer that isdesigned for use in connection with activities such as ice fishing,hunting and camping. The trailer may also be used as an enclosed utilitytrailer for carrying cargo and other items such as motorcycles, ATV's orother equipment.

Referring to FIGS. 2-6, an enclosed multi-functioning trailer isillustrated at 10. The trailer includes a metal frame 12 with a pair oftire, wheel, and axle assemblies 14 and 16 secured thereto. The frame 12supports opposing side walls 24 and 26, opposing “V” nose walls 28 and30, front wall 32, and rear door 34 installed thereon to form the sidestructure of the trailer 10. A trailer roof 36 sits adhered atop walls24, 26, 28, 30, 32, and 34 to enclose the trailer structure 10. A towbar 38 may be connected to the front of the frame 12, which allows fortowing in both wheel and ski mode.

The walls 24, 26, 28, 30, 32, 34 and/or roof 36 may be comprised ofpanels such as laminated composite panels. These panels are insulatedand are also waterproof which prevents mold formation and rotting of thecomponents. The panels are also lightweight and thus contribute to theoverall lightweight nature of the trailer 10.

The use of lightweight materials for the walls and the framework tubingensures the ability to tow the trailer with a vehicle such as an ATV,UTV, snowmobile, or the like. This is advantageous in that the trailercan be towed out on to ice for ice fishing with a lighter weightvehicle, or can more easily be brought camping. The inside of thetrailer may also be equipped with many amenities including beds, stereo,interior lighting, TV, heater, etc. as the frame and wall and floorpanels can support such goods. The trailer may also be outfitted withwindows and vents by way of adapting the wall or ceiling panels withsaid windows or vents. The trailer may also be configured with a solidrear wall or a rear ramp door, openable to provide easy access to theinterior of the enclosed trailer. The trailer is also available in avariety of lengths as the length of the framework tubing and the sizesof the walls is selectively variable.

FIGS. 1 and 9 of the drawings illustrate the frame 12 without the wall,roof, or floor structures for ease of illustration. The frame 12 isconstructed from a plurality of tubular members. The frame 12 may beconstructed of aluminum or like lightweight metal materials, steeltubular members, or a combination thereof. Three larger tubular membersrun from a front to a back of the trailer frame 12 and provide theinitial structure needed to build in the integrated skis. These tubularmembers may be adapted to form the skis themselves, or skis may beintegrally formed thereon or attached thereto. On the bottom side ofthese tubes, a metal (aluminum or steel for example) plate may be weldedto these tubes to provide a larger contact surface with the ground whichbetter distributes the trailer load and may provide angled front andrear edges to for a better angle of attack when towing in ski mode. Italso contemplated that additionally or alternatively, a polymer or othernon-metal material may be used to provide a low-friction wear surface tothe bottom surface of the framework which contacts the ground and actsas a ski or otherwise the skis may be provided with a polymer or othernon-metal bottom surface having a low coefficient of friction.Additionally, the skis may be comprised of replaceable ski runners andski tips.

While three skis 18, 20, and 22 are illustrated, the trailer 10 may andframework 12 may be adapted with a varying number as skis depending onthe configuration of the trailer. The trailer may comprise only 2 skisor may include 4 or more skis. This allows the skis to float up over thesurface being travelled for smoother travel. A height of these tubes isgreater than a remainder of the trailer frame 12 tubular members toprovide ground clearance to the trailer during towing which reducesdrag. The metal tubular sleeves used to mount the tire, wheel, and axleassemblies 14 and 16 can be seen in the trailer frame 12 and sleeves maybe required for stub axles.

FIG. 3 is a side view of the trailer 10 while in wheel mode. It can beseen that the tire, wheel, and axle assembly 14 is in such a positionthat the tire is lower than the frame 12, giving ground clearance toallow for towing on the tires. The left (LH) and middle integrated skis18 and 20 are attached to the frame 12 and do not require anymodification or removal to operate the trailer 10 in wheel mode. Arotation mechanism 19 is operably connected to each wheel 16 and tire 14such that the rotation mechanism moves the wheels themselves vertically(raises and lowers) the wheel when rotated. The rotation mechanism 19 ispositioned on or near the axle and in operable connection with the wheel16 to raise and lower the wheels 16. The rotation mechanism 19 isaccessible for rotation as it is positioned between an outside wall ofthe trailer 10 and the wheel 16 and tire 14. When rotated, the mechanismraises (and conversely) lowers the wheels so that the ground clearanceheight of the frame 12 and thus the trailer 10 can be adjusted, forexample, as called for the by ground surface or other conditions and canbe rotated to such an extent that the wheels are lifted off of theground, and secured by a locking mechanism above plane of the skis 18,20, and 22 thus allowing the trailer to rest on the skis 18, 20, 22 fortowing.

FIGS. 4 and 5 also show the trailer 10 in wheel mode. The tire, wheel,and axle assemblies 14 and 16 mount in such a way that the tires arepositioned outside of (wider than) the integrated skis 18, 20, and 22allowing the tire to run freely with no interference from the skis 18,20, and 22.

The skis 18, 20, and 22 can be integrated into the aluminum frameworkbut may also be separate components that are bolted or otherwise fixablysecured to the trailer structure. The skis may be made out of aluminum,steel, plastic, or any combination of these, or like materials. Towingthe trailer by the use of skis is advantageous as it reduces the groundpressure of the trailer allowing it to be pulled more easily throughdeep snow, wet and heavy snow, or slush.

FIG. 6 now shows the trailer 10 in ski mode. The tire, wheel, and axleassembly 14 has been rotated in such a way to raise the tires off of theground which in effect lowers the trailer 10 down on to the frame 12.The trailer 10 is now resting on the skis 18, 20, and 22, whichdecreases the ground pressure and allows more flotation for the trailer10 as it is towed. This reduces the drag of the trailer 10 and requiresless pulling force to move. FIG. 6 also illustrates the ability tooperate in skis mode while retaining the tire, wheel, and axle assembly14 on the trailer 10. It is not required to remove the assembly 14 whichmakes for a quick and easy transition from wheel to ski mode (and viceversa). A tow-bar 38 has a removable pin which disengages a tubularmember allowing the tow bar 38 to rotate freely at the pin mountsadjoining the tow bar 38 to the frame 12. This allows the trailer 10 tobetter float and adjust to undulating terrain while being towed in skimode.

When skis 18, 20, and 22 are mounted to the trailer or otherwiseintegrated in to the trailer frame 12, this can be done so withoutpreventing or inhibiting the ability to mount the tire, wheel, and axleassembly 14, 16 to the trailer frame 12. This allows the trailer 10 theability to have both the ski and tire assemblies mounted to the trailer10 at the same time. It is not required to change out one system for theother prior to using it. At any place and at any time, the change fromwheel mode to ski mode or vice versa could be completed allowing formaximum flexibility based on weather conditions.

FIGS. 7 and 8 also show the trailer 10 in ski mode, but with the tire,wheel, and axle assemblies 14 and 16 removed. Such that while notrequired, the assemblies may be removable. The trailer 10 operates inthe same manner as it would in any other configuration allowing for skimode but with assemblies 14 and 16 removed, a significant percentage ofthe overall trailer's 10 weight is removed. This allows for reducedground pressure, easier towing, and the ability to tow the trailer 10 inand to areas where it could otherwise not go (e.g., softer ground orless supporting ground surface such as ice).

Additionally, or alternatively, trailer 10 is configured for removaland/or rotation of the tire, wheel, and axle assembly 14 to allow fortowing of the trailer on the integrated skis. To allow usage of eitherthe tire mode or skis mode, the trailer axle assembly can be rotated toadjust the ground clearance of the trailer. At some point during therotation, the tires raise up off of the ground allowing the trailer 10to sit on the skis 18, 20, 22 to be towed in ski mode.

It is also possible that a permanently installed solid axle could beutilized instead of the stub tire, wheel, and axle assemblies 14 and 16illustrated here. Since the solid axle is not easily removable, thisassembly would remain always attached and installed on the trailerwhether operating in ski or wheel mode.

Axle configurations include removable stub axles (two or more),permanent stub axles (two or more), or permanent full axles (one ormore). The changes to the axle assembly type allows for the trailer 10to have different amounts of ground clearance while in wheel mode andfor different operating configurations while in ski mode. The removablestub axles allow for the tire, wheel, and axle assemblies 14, 16 to besimply removed from the trailer 10 to lower the weight of the trailer 10while in ski mode. The axle assembly may rotate lowering the trailerframework to the ground which would then raise the tire off the groundallowing for the axle to be removed. Alternatively, the perimeter of thetrailer 10 can be supported by jacks or another means raising the tiresoff the ground allowing the axle assembly to be removed. The jacks wouldthen be lowered which would allow the trailer frame 12 to be set on theground. Permanent stub or full axles allow the tire, wheel, and axleassemblies 14, 16 to rotate up and are fixed in a location where thetires are off the ground to allow for ski mode. Permanent axle designsdo not require the removal of the sometimes heavy axle assemblies tooperate in ski mode.

A wheel lifting mechanism is provided to raise and lower the wheels,thus allowing for the conversion between the wheeled mode and the skimode for towing. As illustrated in the figures, an arm can be connectedto the axle assembly for rotating the assembly to raise or lower thewheels. Examples of addition or alternative mechanisms for raising orlowering the wheels include, but are not limited to a winch may operablyconnected to the assembly for rotation for raising or lower wheels; anelectric or hydraulic cylinder may be used to raise or lower the wheels.Supporting and lifting and lowering the trailer frame 12 may also bedone by using independently mounted jacks or lifting mechanisms thatremove pressure placed on the running gear, allowing for the runninggear to be uncoupled from the frame and allow for the rotation of therunning gear which would lower the frame. The trailer 10 can utilizeindependently rear mounted jacks that are configured to lift and lowerthe enclosure and the running gear can be unpinned and allowed to rotatefreely which to allow the frame 12 to lower to the ground. The wheellifting mechanism may also comprise a cable or strap winch.

It is also possible that the skis construction could be completed byutilizing wider frame tubular members which would eliminate the use ofthe additional plate to create a wider contact area. The skis may alsobe created by mechanically fastening or adhering additional metal orplastic components to the frame 12 to create the larger contact area. Itis also an option to line the bottom of the metal skis with a plasticmaterial such as HDPE or another material having a reduced coefficientof friction to provide a surface which reduces drag and to provide awear surface which is easily replaced in order to maintain the integrityof the frame 12.

Referring now to the tow-bar 38 noted previously, the tow bar isillustrated in further detail in FIGS. 10-16. The tow-bar 38 is aconvertible trailer towing tongue 38, hereafter referred to as “tow-bar”38. The tow-bar 38 may attached to the frame 12 (and also attached tothe frame of any type of pre-existing trailer such as an open, enclosed,utility, ice fishing, camping, or trailer of the like). The tow-bar 38assembly is configured for coupling the trailer frame 12 to a towvehicle. It is convertible between rigid and pivoting configurations.

In the rigid configuration, the assembly represents a standard tongue aswould be found on the front of a road-going trailer frame. The tongue issupported both longitudinally and laterally with respect to the trailerframe 12. The rear attachment of the tow-bar 38 may be one or morepoints in such a configuration as to provide lateral stiffness.Longitudinal stiffness is provided by engaging a rigid member 120between two or more points, where the rigid member engages at least onepoint attached to the trailer frame and at least one other pointattached to the tow-bar 38. Thus, the tow-bar 38 may be attached to theframe 12 at two or more points, and for example, three points in totalincluding the rigid member 120 connection as illustrated in the figures.

FIG. 11 illustrates a side view of the tow-bar 38 and trailer frame 12in a rigid configuration. In this configuration, pins may be used inattachment points 122, 124, 126, and 128 to fix the tow-bar 38 in itslocation so that it is not allowed to pivot on attachment points 122 and124. The plurality of attachment points that are pivotable include pinand bolt connections. For example, the tow-bar 28 is rotatably connectedto the frame work and is configured to pivot or rotate about theattachment points while the rigid member 120 is also configured torotate or pivot about its attachment point by way of rotation pins.Further, the rigid member can be secured to a bracket by the alignmentof apertures in the member 120 and the bracket and the insertion oflocking pins there through. Thus, as illustrated in the figures, therigid member can be secured in a substantially horizontal position withthe tow-bar or in a substantially vertical position, with or without thetow bar 38. The “bracket” may also be an integral part of the frame, andthe secured storage position may be other than a substantially verticalposition. The tow-bar 38 may have a storage position that issubstantially upwardly such that the tow-bar 38 does not interfere withframe 12 during normal motion or so similarly, the rigid member 120 doesnot interfere with the tow-bar 38. For example, in instances where afuel tank is mounted up front of the trailer 10, the storage positionhas the rigid member 120 at about 34° upwardly from horizontal position.

In FIGS. 12 and 16, close-up views of the tow-bar 38 are presented. Thetow-bar 38 is constructed from aluminum tubing and channels to form anA-frame type weldment where a center tube section running longitudinallyis welded to two tubes which extend outward both laterally andlongitudinally towards the trailer frame 12 (forming an “A” shape). Thecenter tube section is used to mount the trailer coupler and isconfigured with a mechanism to removable attach to a standard mount onvarious vehicles. At the ends of the A-frame tubes, channel or a clevismay be secured to or welded to the tubes to provide a mounting locationat the pivot attachment points 122 and 124. Thus, one or more verticallyoriented tabs having an aperture therein for receiving a pin to therethrough to provide the pivot axis may be provided.

The trailer frame 12 may then have parts secured to or welded to it toprovide the mating attachment point for the tow-bar 38. The pivotattachment points 122 and 124 are designed and installed in such a waythat they are on the same axis to allow the tow-bar 38 to rotate freelyupon the axis created by these points. A rigid member 120 has two ormore attachment points. A front rigid member attachment point 126connects the rigid member to the tow-bar 38. A rear rigid memberattachment point 128 connects the rigid member to the trailer frame 12.Additional attachment points could be used to further attach the rigidmember 120 to either the trailer frame 12 or the tow-bar 38 or both. Theattachment points could use either pins or bolts with nuts forfastening. As illustrated in FIG. 16, a bracket 132 is secured to theframe 12 and is configured to provide a pivotable connection for therigid member 120 and to provide one or more locking points for the rigidmember. The pivoting connection or attachment of the rigid member 120 tothe frame 12 via the bracket 134 comprising a pivot pin or bolt securingthese components. Locking points 134 are pairs of opposing aperturesthat align with pairs of opposing apertures on the rigid member 120 toreceive a locking pin. When the locking pin is inserted into the alignedpairs, the rigid member 120 can be secured to the tow-bar 38 (and thusin a position parallel to the tow-bar 38) and/or can be secured in avertical position such that the rigid member 120 and/or the tow-bar arerotated upwardly. The rigid member 120 is configured to rotate with thetow-bar 38 and also to rotate independently of the tow-bar 38. Otherpivoting configurations for connecting the tow-bar 38 and the rigidmember 120 to the frame 12 are contemplated and include attachmentpoints utilizing pivot pins for connecting flanges or elements of thetwo-bar to the frame 12.

In the pivoting configuration, the assembly represents a tow-bar aswould be found between a utility sled and a tow vehicle. The tow vehiclecould be a car, truck, ATV, UTV, snowmobile, or the like. In thispivoting configuration the tow-bar 38 is also providing lateralstiffness as in the rigid configuration. However, the tow-bar 38 isallowed to pivot up and down with respect to the plane represented bythe trailer frame 12, through an axis lateral to the trailer frame 12.This may be accomplished by designing the attachment points between thetow-bar 38 and the trailer frame 12 such that they can pivot along thislateral axis. The front towing point connection to the tow vehicle canbe made with any common style of trailer hitch connection. In thispivoting configuration, the trailer frame 12 could be supported over theground by skis 18, 20, 22, and follow the ground. Thus, the pivotingnature of the tow-bar 38 allows the trailer to behave as a sled and notsubstantially require “tongue weight” to be carried on the hitch of thetow vehicle.

The tow-bar 38 is configured with an easy means of pivoting up and outof the way when not in service. This may be accomplished by uncouplingthe attachment point(s) of the rigid member and pivoting the rigidmember into a vertical or substantially upwards stowing position. Thetow-bar 38 may also then be pivoted into a vertical or substantiallyupwards stowing position. The rigid member 120 and tow-bar 38 can pivotindependently or together to the stowing position. The rigid member 120and tow-bar may be retained in such a position through the use ofpin(s), a padlock, strap, latch, magnets, or the like. By allowing therigid member 120 and tow-bar 38 to be stowed in a substantially verticalposition or upwards, it keeps the tow-bar 38 and the rigid member 120out of the snow, ice, water, mud, or other elements present on theground.

FIGS. 13-15 illustrate the tow-bar 38 in a pivoting configuration. Itcan be seen that rigid member 120 is rotated upwards and is decoupledfrom the tow-bar 38 at attachment point 126. The rigid member 120 isadapted with a pair of opposing apertures on each of the terminal endsof the rigid member 120. As illustrated in FIG. 15, the tow-bar 38 hasupwardly extending prongs also having a pair of opposing apertures suchthat one terminal end of the rigid member can be positioned between theprongs on the tow-bar 38 such that the pairs of opposing apertures onthe rigid member 120 and the tow-bar 38 are aligned and a pin can beinserted therethrough which secured the rigid member 120 to the tow-bar38. Removal of the pin would allow for the pivoting of the rigid member120 upwardly and way from the tow-bar 38 about a similarly constructedpivotable connection with the framework as pins can be inserted into thealigned opposing apertures of the attachment points on the tow-bar 120and the trailer framework 12 to pivotably connect the tow-bar 12 to theframework 38.

The rigid member 120 could then have a secondary attachment point thatwould hold it in the upwards position to allow the tow-bar 38 to rotatefreely at attachment points 122 and 124. This could be accomplished byusing a pin or bolt in a secondary mounting bracket or by using a cableor other similar means to hold the rigid member 120 in its upwardposition. With the rigid member 120 decoupled from the tow-bar 38, thetow-bar 38 is allowed to rotate on attachment points 122 and 124 whichcreate a single axis of rotation. The figures illustrate the tow-bar 38rotated upwards so that the top plane of the tow-bar 38 is not at thesame orientation as the top plane of the trailer frame 12 but insteadintersects it. In the pivoting configuration, the trailer frame 12 willrest on the ground which eliminates nearly all of the hitch weight onthe tow vehicle.

The tow-bar 38 may also be configured for “tool-less conversion” betweenthe rigid and pivoting modes. As such, the rigid member attachmentpoint(s) between the frame 12 and tow-bar 38 may be connected throughuse of tool-less pin insertion. This provides some security againsttheft and conserves space around the trailer 10. The tool-less removalby way of pins at the pivoting attachment points and rigid memberattachment points for securing the components can be easily removed forremoval and storage of the tow-bar 38. Alternatively the pivot pointscould be bolted using traditional fasteners, and still require loweffort to remove.

A clamp type attachment could also be used to connect the rigid memberat its attachment point(s) such that the attachments can be removedwithout the use of additional tools but remain secure enough for towingthe trailer 10. The rigid member 120 may be retained by a clamp methodas an alternative or in combination with a pin or bolted method. In thisdesign, the rigid member 120 would rest on both the trailer frame 12 andthe tow-bar 38 and a clamp would come over the tow-bar and then betightened to create the rigid configuration. Examples of pivotableattachment mechanisms for connecting the tow-bar 38 to the framework 12and of connecting the rigid member 120 to the framework 12 include butare not limited to bolts, screws, pins, clamps, or a combination thereofsuch that the tow-bar is removably attachable to the framework andwherein bolts, screws, pins, clamps or a combination thereof can be usedto prevent pivoting or limit pivoting of the tow-bar about the pivotableconnection when in use.

The rigid member 120 may be positioned laterally or at a different anglein relation to the trailer frame 12 instead of longitudinally. Thisallows the rigid member 120 to again be retained at the attachmentpoints by the use of pins or bolts or be attached through the use ofclamps.

The tow-bar 38 may have an integral transverse cross member located nearthe trailer frame. The rigid member then locks between the cross memberand the trailer frame to complete the rigid configuration. This allowsthe rigid member to again be retained at the attachment points by theuse of pins or bolts or be attached through the use of clamps.

The tow-bar 38 may be constructed in such a fashion that the componentsused to create the tow-bar 38 may run longitudinally, only with nolateral extension in relation to the trailer frame. This creates more ofan inline tow-bar 38.

The tow-bar 38 may be constructed in such a fashion that the componentsused to form the tow-bar 38 are oriented such that they extend bothlaterally and longitudinally and utilize what is commonly referred to asan A frame coupler. This would eliminate the requirement of alongitudinally running center component to mount the hitch coupler.

The tow-bar 38, while in the rigid configuration, may be positioned suchthat the top plane of the tow-bar 38 is not in the same orientation ofthe top plane of the trailer frame 12 but intersects it.

Although the present disclosure has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the disclosure.

The invention claimed is:
 1. A towable trailer comprising: a trailerframework configured for supporting a trailer enclosure thereon, whereinframework comprises: a plurality of first tubular members positioned ina direction of travel and a plurality of second tubular cross membersextending between and connecting at least two of the plurality of firsttubular members; at least one pair of ground engaging wheels operablymounted thereon; at least one substantially smooth bottom surfaceintegral to the framework and extending along at least a portion of thelength of at least one of the plurality of first tubular members in adirection of travel and the bottom surface positioned within the spacebetween wheels of the at least one pair of wheels; a wheel liftmechanism configured to adjust the position of the ground engagingwheels vertically with respect to the framework so as to raise and lowerthe wheels with respect to the ground; and wherein the towing mechanismis selectively interchangeable between a wheeled tow and a ski tow, suchthat the wheels are used for towing in a first position and when thewheels are raised above the first position, the trailer is configured torest on the at least one substantially smooth bottom surface integral tothe framework such that the bottom surface of the framework engages witha ground surface for towing the trailer in a ski mode.
 2. The towabletrailer of claim 1, wherein the frame work is constructed of aluminumtubing.
 3. The towable trailer of claim 1, wherein the trailer enclosureis comprised of at least one of a plurality of vertical walls, a floorpanel and a roof panel and wherein the panels are constructed of alightweight composite material.
 4. The towable trailer of claim 1,wherein the substantially smooth bottom surface comprises at least oneski having an upturned edge, and wherein the bottom surface of theframework comprises at least two skis positioned on opposing sides ofthe framework and oriented in the direction of travel of the trailerwhen towed.
 5. The towable trailer of claim 4, wherein the skis arecomprised of a plastic material, a metal material, or a combinationthereof and comprise an upturned edge in the direction of travel topromote sliding during towing.
 6. The towable trailer of claim 5,wherein the skis are coated with a material configured to reduce thecoefficient of friction of the surface of the skis.
 7. The towabletrailer of claim 1, where the wheels are not removed when the trailer istowed in ski mode.
 8. The towable trailer of claim 1, wherein theframework is further configured with a removable and selectivelypivotable tow-bar configured for removable and pivotable attachment tothe framework and removable connection to a tow vehicle, where thetow-bar can be rotated upwardly about connection to the framework forstorage when not in use.